نتایج جستجو برای: aryl 2 nitrovinyl
تعداد نتایج: 2535145 فیلتر نتایج به سال:
The direct synthesis of aryl triflones, that is, trifluoromethanesulfonyl arenes, was achieved through the trifluoromethanesulfonylation of benzynes. The trifluoromethanesulfonyl group, one of the fluorinated functional groups, is a highly electron-negative and mild lipophilic substituent. Aryl triflones have high potential in the synthesis of bioactive compounds and specialty materials. The tr...
We describe a new chromogenic substrate and assay for determining N-acetyl-beta-D-glucosaminidase (EC 3.2.1.30; NAG) activity in normal and pathological human urine. The novel substrate, ammonium 5-[4-(2-acetamido-2-deoxy-beta-D-glucopyranosyloxy)-3- methoxyphenylmethylene]-2-thioxothiazolidin-4-one-3-ethan oate (VRA-GlcNAc), is prepared by condensation of vanillyl N-acetyl-beta-D-glucosaminide...
3-Aryl-2H-azirines react with acylketenes, generated by thermolysis of 5-arylfuran-2,3-diones, to give bridged 5,7-dioxa-1-azabicyclo[4.4.1]undeca-3,8-diene-2,10-diones and/or ortho-fused 6,6a,12,12a-tetrahydrobis[1,3]oxazino[3,2-a:3',2'-d]pyrazine-4,10-diones. The latter compounds, with a new heterocyclic skeleton, are the result of the coupling of two molecules of azirine and two molecules of...
Trimethylsilyldiazomethane (TMS-CHN2) reacts readily with hetaryl thioketones to give sterically crowded 2-trimethylsilyl-4,4,5,5-tetrahetaryl-1,3-dithiolanes with complete regioselectivity at -75 °C as well as at rt. Thiofluorenone, a relatively stable and highly reactive aryl thioketone, yields upon treatment with TMS-CHN2 at -60 °C the corresponding 1,3,4-thiadiazoline. This unstable cycload...
Gold(III)-catalyzed activation of alkynes has been applied for the synthesis 2,5-disubstituted furans from substituted 5-methoxy-hex-3-yn-2-ols. Mechanistically, reaction proceeds via an allenyl carbocation intermediate followed by 5-endo-dig cyclization. The high-yielding, open-air, room temperature conditions to synthesize a series alkyl, aryl, and hetero aryl-substituted provide uniqueness s...
N-Tosyl diazoketamines were prepared by addition of the ethyl alpha-diazoacetate anion to N-sulfonylimines. The diazo decomposition of the diazoketamines with Rh(2)(OAc)(4) complex resulted in aryl migration to give alpha-aryl-beta-enamino esters in good yields and high stereoselectivity. The effect of the catalysts on the migratory aptitude of 1,2-aryl over 1,2-hydride migration was studied. A...
beta-Aryl eliminations from a series of iminyl complexes to form rhodium aryl complexes and free nitriles are reported. Iminyl complexes [Rh(PEt3)3(N=CArAr')] were prepared from [Rh(COE)Cl]2, PEt3, LiN(SiMe3)2, and the imines HN=CArAr'. One example of these complexes was characterized by X-ray diffraction. Heating of these complexes in cyclohexane generated the rhodium aryl complexes and free n...
Preliminary examination for the structure-activity relationship of quinone monooxime derivatives on cytotoxicity against HeLa S3 cell and further trials using eight different cell lines suggested that 2-aryl-6,7-methylenedioxy-1,4-naphthoquinone-1-oxime methyl ethers, carrying 2-methoxy-4,5-methylenedioxyphenyl, 7-methoxy-2-methylbenzofuran-4-yl, and 2-methoxycarbonyl-3,4-dimethoxyphenyl as the...
Abstract A new method for the fast synthesis of diverse 4-aryl-6-cycloamino-1,3,5-triazin-2-amines was developed. The is performed under microwave irradiation in a one-pot manner from cyanoguanidine, aromatic aldehydes, and cyclic amines. Their three-component reaction presence hydrochloric acid produced dihydrotriazines, which were then converted (without isolation) into targeted compounds via...
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